If you're an evangelical Christian, there's a good chance your church or youth group is planning a missions trip this year.

In fact, millions of American Christians travel abroad each year on short-term missions. But are these trips effective? What impact do they have on long-term evangelism around the world? CBN News has traveled the world to get the answers to these questions from career missionaries.

Click the player to watch the report from CBN News Reporter Chuck Holton followed by Pat Robertson's comments on the debate concerning short-term versus long-term missions.

The youth group mission trip has become a summer fixture for Christian churches around America. They raise support in a variety of ways, then head out to take the gospel to unreached people around the globe. When they return, the kids can't wait to share their experiences. They're fired up - at least for awhile.

A Burden, Instead of Helping

And what about the mission fields they visit? Ask around and you might find a different perspective.

"There have been teams of young people that have come down, their hearts are in the right place, they love God, but a team of 125 people, the logistics are huge on the missionary family," explained Wilma Forster, a career missionary. "It creates a burden instead of a help."

"As a missionary in the bush of Africa, I've got everything I can do to be a pastor of a local church," said full-time missionary Shane Russell. "To help the people, to meet the needs of my own family, and with limited funds in that environment, it does put a strain on you."

Number of New Missionaries Declining

One argument in favor of short-term trips is they lead to career choices in overseas evangelism. However, according to a study by the American Society of Missiology, that connection is not so clear. The study points out that while short-term missions have surged in the last twenty years, the number of new missionaries has actually declined.

In Panama, CBN News met one individual who recently answered the missions call. Philip Brummett relocated his family a couple of years ago after a short-term trip introduced him to the Kuna Indians.

"I'll always have a special home in my heart for short-term missions, because if it wasn't for short-term missions, we wouldn't be here," he said.

But once he began living among the Kuna, Brummett started seeing the effect of short-term groups on the tribe.

After one mid-sized church sent their youth group down for a week, Brummett was amazed at the cost.

"The money that they spent on food alone was enough to pay for one of our week trainings for the Kuna on the island," he explained.

But what about evangelism? Do these trips usually result in people being saved and taking that change back home?

"I've seen someone show the Jesus film over three nights and a handful of people got saved," Brummett responded. "And the last night they let a Kuna pastor that preached and thirty five people got saved. He preached to his own people in his own language with his own heart, and that had a tremendous impact."

"Do you want to be saved, if so raise your hand," Russell said. "Everybody raises their hand, and then they pack up and leave. And then the following Sunday you don't see these people in church. I think a lot of people in our community have been saved numerous times, but there's no change in their life."

Missions Funding On The Decline

A more disturbing trend is that overall giving to missions has been declining lately. That means it takes many missionaries twice as long to raise the support needed to make it to the field.

Stu Kinniburgh runs the Master's Mission. It is a huge center that trains missionaries for long-term service. He says the priority is full-time not short term.

"There are still over 6,000 unreached people groups worldwide," he said. "Many of these simply can't be reached by short term missions. Giving is down. Only two percent of money given to churches goes towards missions today. Of that, half goes to relief work, not church planting."

"The solution is more long-term missionaries," Russell explained. "We need more career missionaries. But what we see is the other end of the spectrum. Every year the money spent on short-term missions is increasing exponentially. The church in America sooner or later sit back and figure out that short-term missions are not working.

"Because the expense the church is going through yearly to send people overseas, we should be seeing more career missionaries," he continued. "In fact, the opposite of that is true: we're seeing less and less long term missionaries."

Re-Thinking Mission Focus

None of the missionaries CBN News interviewed said that churches should stop their short-term programs, but rather need to re-think their focus and make sure missions dollars are being spent wisely - and not neglecting those who have given their lives to full-time service.

"Experts coming down are helpful, if they're coming down to help and not just for a vacation," Forster said.

"Our hope is that we give them the resources that they need and let them take it for themselves," Brummett explained.

"There is something in giving your life to something bigger than yourself," Russell said. "It is my life, and in every aspect of my life it is to reach people for Christ and to see them grow in the faith."